The conventional lipstick case has the slide tube seat engaged directly with the inner tube sheath which revolves for operating the slide tube seat up and down. However, the cover tube is provided separately.
Such construction as described above is defective in design.
The cover tube easily disappears once being separated, so that it loses its effective protection of the lipstick.
The revolving of the inner tube sheath, which operates the slide tube seat up and down does not have the function of holding its postion. Therefore, it causes the slide tube seat to retract while in use.
The protrusion of the slide tube seat has an improper length for fastening firmly within the inner tube sheath, so that it is easy to shake and destroy the lipstick.